Al-Kāfi - Volume 3 > Preferences for Relatives and Those of Them to Whom Zakat Cannot Be Paid
Hadith #8

8ـ مُحَمَّدُ بْنُ أَبِي عَبْدِ الله عَنْ سَهْلِ بْنِ زِيَادٍ عَنْ عَلِيِّ بْنِ مَهْزِيَارَ عَنْ أَبِي الْحَسَنِ (عَلَيْهِ الْسَّلام) قَالَ سَأَلْتُهُ عَنِ الرَّجُلِ يَضَعُ زَكَاتَهُ كُلَّهَا فِي أَهْلِ بَيْتِهِ وَهُمْ يَتَوَلَّوْنَكَ فَقَالَ نَعَمْ.

8. Muhammad ibn abu ‘Abd Allah has narrated from Sahl ibn Ziyad from Ali ibn Mahziyar from who has said the following: “I once asked abu al-Hassan, ‘Alayhi al-Salam, about a man who pays all of his Zakat to his relatives who have accepted you as their Waliy (one who possesses Divine Authority). He (the Imam) said, ‘Yes, he can do so.’”